From Lab to Real-World: Unraveling Coconut Shell Activated Carbon’s Efficiency for Low-Concentration TCE/PCE in Indoor Air

Low-concentration trichloroethylene (TCE) and tetrachloroethylene (PCE) indoors pose a significant threat to human health due to their potent carcinogenic properties. However, existing research has predominantly focused on high-concentration scenarios in industrial settings, offering limited guidance for indoor air purification. This study investigated the adsorption mechanisms and performance regulation of coconut shell activated carbon for TCE/PCE through experimental analysis, molecular simulations, and dynamic modeling. Experimental results demonstrated that PCE, characterized by its non-polar nature and high boiling point, exhibited a substantially higher adsorption capacity than TCE. Increased humidity induced competitive adsorption between water molecules and pollutants, reducing the adsorption capacity of PCE by approximately 30%. Molecular simulations validated that water molecules occupied the active sites of oxygen-containing functional groups and pores, impeding the diffusion of TCE/PCE, while the non-polar surface of activated carbon preferentially adsorbs PCE. A dynamic prediction model developed in this study accurately forecasted breakthrough curves under varying pollutant concentrations, temperatures, humidities, and air velocities and quantified the service life of activated carbon. Response surface methodology revealed that controlling inlet concentrations (TCE < 7 ppb, PCE < 30 ppb), air velocity (<1 m/s), humidity (<50%), and temperature (<25 °C) can extend the service life of activated carbon to 3–5 months.